The icy dirt balls - between just five kilometers and 20 kilometers across - emerge from massive discs of gas and dust around the stars, the raw material for new planets. Welsh said the exocomets are formed from these scraps left over from planet formation.

“This is like the missing link, the missing piece in the puzzle. And it reinforces all the planetary formation theories because all the planetary formation theories say you should end up with left-over comets and left-over big hunks of rock, asteroids, and that sort of thing,” he said.

Comets Discovered Around Distant Solar Systems

At the American Astronomical Society's meeting in Long Beach, California, Welsh reported that he and his colleagues found spectrographic signatures of the six new exocomets orbiting six very young type-A stars, which are only about 5 million years old.

Although not all the stars harbor exoplanets, the debris disk means they could be present. Welsh said it suggests that across the universe, exoplanets and exocomets co-exist, as they do in our own solar system. “It looks as though they are quite common things.”

Welsh said that if, as experts theorize, comets could have seeded the primordial earth with organic carbon material and water, then comets also may be the key to life elsewhere in the universe. “If comets are universally distributed around, then you could say that the incidence of life could be higher on other planets than we ever thought.”

Back in our own solar system, comets continue to put on celestial shows for Earth-bound observers. People in the northern hemisphere will be able to see an unusual comet in late November of this year, with the highly anticipated appearance of Comet ISON. The newly-discovered comet is predicted to shine as brightly in the night sky as the full moon.

Then core collapse causes the (wide-binary) binary companion stars, planets, moons and planetesimals to spiral out by feeding on the energy and angular momentum of their close-binary pairs which spiral in until they merge, forming solitary bodies.

As a binary companion star spirals out from its progenitor star, the binary planetesimals formed at the barycenter (which orbit the progenitor star) also spiral out, but some get trapped in inner or outer resonances of giant planets.

In our own solar system, Proxima (Centauri) at 270,000 AU may be the companion star to our former central binary pair with the solar-system barycenter at 29,600 AU, and the planetesimals formed at the barycenter spiral out until they merge, forming the inner Oort cloud. And the asteroid belt (Jupiter's inner resonances) and Kuiper belt (Neptune's outer resonances) are merely two solar system buckets that trapped these planetesimals, some which collided to form dwarf planets. The other solar system resonances interfere with one another: Jupiter's outer resonances interfere with Saturn's inner resonances and etc. Then our central binary pair merged at 4,567 Ma, forming the chondrules and short-lived isotopes and Proxima's binary pair may have merged at 542 Ma, bringing on the Cambrian Explosion of life.

by: Rob Swift from: Great Britai

January 13, 2013 4:08 PM

The missing link, what we are all waiting for, is yet to be found. ( in deep space. )

At this year's annual South by Southwest film and music festival in Austin, Texas, some musicians from Mali were on hand to promote a film about how their lives were upturned by jihadists who destroyed ancient treasures in the city of Timbuktu and prohibited anyone from playing music under threat of death. As VOA’s Greg Flakus reports from Austin, some are afraid to return to their hometowns even though the jihadists are no longer in control there.

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At this year's annual South by Southwest film and music festival in Austin, Texas, some musicians from Mali were on hand to promote a film about how their lives were upturned by jihadists who destroyed ancient treasures in the city of Timbuktu and prohibited anyone from playing music under threat of death. As VOA’s Greg Flakus reports from Austin, some are afraid to return to their hometowns even though the jihadists are no longer in control there.

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American warplanes joined Iraq's battle against the so-called 'Islamic State' in northern Iraq late Wednesday, as Iraqi ground troops launched a massive assault on Tikrit. Analysts say the offensive could take the coalition a step further towards Mosul, the largest city held by Islamic State forces. Others say it could also deepen already-dangerous sectarian tensions in the region. VOA's Heather Murdock has more from Cairo.

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One of the films that drew big crowds last week at the annual South by Southwest festival in Austin, Texas, tells the story of the last human being to stand on the moon, U.S. astronaut Eugene Cernan. It has been 42 years since Cernan returned from the moon and he laments that no one else has gone there since. VOA’s Greg Flakus reports.